Effect of Seasonal Variation on Blood Lead in Health Children / 实用儿科临床杂志

Objective To explore effects of seasonal variation on blood lead in children.Methods Anodic stripping voltammetry(ASV) was used to detect blood lead level in children.The enrolled children were divided into 4 groups as follows:young children(ages 1 month to 3 years);preschool(ages 3 to 6 years);school(ages 6 to 12 years);teenagers(ages 12 to 18 years),and children′s blood lead level and lead poisoning rates were analyzed in the light of seasonality.Results Total 13 233 children were observed,aged from 1 month to 18 years old,8315 males,4918 females.The average blood lead levels were 60 ?g/L,the 5~(th) and 95~(th) percentage was 19,138 ?g/L.The rate of lead poisoning in children was 14.8%,with the majority of low-grade(?~2=116.3125 P

Effect of chronic cigarette smoking on large-conductance calcium-activated potassium channel and Kv1.5 expression in bronchial smooth muscle cells of rats / 生理学报

To investigate the role of potassium channels in the pathogenesis of airway hyperresponsiveness induced by cigarette smoking, the alteration in expression of large-conductance calcium-activated potassium channel (BKca) and voltage-dependent delayed rectifier potassium channel (Kv1.5) in bronchial smooth muscle cells were investigated in chronic cigarette smoking rats. Airway responsiveness was determined, hematoxylin and eosin staining, immuno-histochemistry, in-situ hybridization and western blot techniques were used. The results showed: (1) Chronic cigarette smoking down-regulated the protein synthesis and mRNA expression of BKca and Kv1.5 in bronchial and bronchiolar smooth muscles. (2) BKca decreased more markedly than Kv1.5 in bronchi, but there was no difference between them in bronchioli. (3) No changes in the expression of these two potassium channel proteins were found in extracted cell membrane protein from lung tissue. The results suggest that chronic cigarette smoking can down-regulate the levels of BKca and Kv1.5 in rat bronchial smooth muscle cells in vivo, which might contribute to the mechanism of airway hyperresponsiveness induced by cigarette smoking.

Observation of the Expression of HCV NS 5 Antigen in vitro by the SABC Immunological Techniques and Gold-labeled Colloid Electron Microscopy Method / 中国病毒学

To study the expression of HCV non-structure 5 antigen in vitro, a human HepG2 cell line was incubated with a HCV RNA positive serum. The S ABC i mmunological techniques and gold-labeled colloid electron microscopy method wer e employed to examine for the viral proteins in those cells. The HCV non-struct ure 5 antigen was first detected in the HepG2 cells at 72 hours post incubation. The antigen was continuously observed in the cytoplasm or on the membrane as we ll on the cell wall of the HepG2 cells even after 1, 2, 3 and 4 weeks post incub ation. The observation of HCV non-structure 5 antigen continuously expressed in the HepG2 cells strongly indicates that the cells may have been infected by HCV virus and the virus may have replicated in the cells. Therefore, the HepG2 cell line may be served as a potential host for establishment of HCV infection and p ropagation in vitro.